Sudan on Monday jailed a journalist for reporting the alleged rape of a female opposition activist by security forces, her lawyer said, in a trial that has already seen one reporter imprisoned.

"The court in Khartoum sentenced Amal Habani to pay 2,000 Sudanese pounds ($600) or go to jail for one month, and she chose to go to jail. She is on her way there now," Hassan Abdullah al-Hussein told AFP.

Habani and the editor of Al-Jarida newspaper, Saad al-Din Ibrahim, for whom she worked before being sacked, were both found guilty of publishing lies and violating Sudan's ethical code, said Hussein.

Ibrahim was ordered to pay a fine of 5,000 Sudanese pounds.

Earlier this month, Fatima Ghazali became the first of several journalists and editors to be tried for articles written about Safiya Ishaq, an activist who claimed in videos posted online that she was raped repeatedly by three security officers after her arrest in Khartoum in February.

Ghazali was also imprisoned for one month after refusing to pay a fine.

Another five journalists and editors who have been charged with the same offences are waiting for their cases to be heard.

Reporters Without Borders last month accused the authorities in north Sudan of harassing and prosecuting journalists in an attempt to stop them making embarrassing revelations about human rights violations by the security forces.